Layout appropriateness is a computer science concept that relates to the design of user interfaces. In designing interfaces, and principally graphical user interfaces, attention must be paid to the manner and amount of information presented to the user. A well-designed user interface will be easy to navigate and, therefore, will enhance the efficiency of the task(s) for which it has been designed.

There are a number of factors that influence the appropriateness of an interface layout. The distance between task buttons or menu items--also known as widgets--is an important influence. For example, it can be tedious and even physically difficult or frustrating for the user to negotiate large distances with the mouse or the tab controls in successive tasks. Layout appropriateness measures the efficiency of a user interface layout, based on the frequency of user tasks and a measure of the distance a user must move in order to accomplish these tasks. The distance can be empirically measured, based on a formula called Fitt's Law.

The empirical measurement involves the drawing of lines between widgets. The amount of ink used to draw the line is related to the cost of the transition, that is, to the effort on the part of the user to effect the transition. A thick line represents a short and frequent transition. A thinner line represents a long but frequent transition. Thin grey lines represent transitions that do not have much influence on the efficiency of the entire procedure. Intuitively, the aim is to increase the proportion of thick lines for frequent tasks and thinner or grey lines less frequent or less relevant tasks.

The above drawing exercise would be employed by a designer in testing out different interface arrangements. Relying merely on visual inspection of an interface to assess its ease of use is not a sound design practice. Current research efforts are extending the layout appropriateness determination to multi-screen interfaces.